Siemens Deka 630cc/660cc Direct fit? Best Place to buy?

[URquattroGus]

What he says

[Ross]

Not trying to start a debate here (and all things were not equal as Corey was involved so I didn't 100% trust anything I was told)...

But, with a brand new set of 630cc's Automark wouldn't tune the car with my 3071R. RS2 injectors were used instead. The injectors were aparrently too big. They were in fact bought by me from Tom, who I believe used a set on his MRC tuned Coupe, and were a recommended option by them.

I would speak directly to MRC - if they can map them to get an effective result, then there ya go, just need word from them really. They'll never be the most ideal but if they are adequate and you'll never know the difference then it's your choice...

Due to the self-destruction of my engine I didn't ever use the injectors - my brother has them ATM, but if you wanted them PM me. Don't think they have ever been used except for an attempt at mapping them.

[prj]

The fact that automark said "they were too big" has nothing to do with them being to big

Anyway, the main issue is that they are inconsistent at low pulsewidth. Their latency compensation gets way off, and because of that without systems of WBO2 feedback they will be inconsistent.

1.5ms is just crap. Even stoneage Bosch injectors can do better and new ones do 0.7ms.

[Billman]

i tried to find a proper datasheet for bosch injectors but simplly could not find anythhing about min pulsewidth values.

I found this about the siemens for those who are interested





also found this with many bosch part numbers

http://www.usrallyteam.com/content/products/injector/Bosch_Injector_data.xls

[URquattroGus]

Is 1.5ms correct?

http://www.bmotorsports.com/shop/product_info.php/products_id/448

http://injector-rehab.com/shop/lag.html

[Billman]

one states minimum linear at 1.5 the other at 1.3ms.

[URquattroGus]

http://cgi.ebay.co.uk/5-EV14-Volvo-B...item5639777376

http://cgi.ebay.co.uk/5-EV14-Volvo-B...item5643cf7991

How about using EV14 650cc or 750cc with adaptors then? too big? Price seems reasonable.

Sorry if anyone is fed up of this thread

[URquattroGus]

Yes sorry, I posted before someone posted the official data sheet.

Prj is correct.

[Error404]

Maybe I am being thick here but if the only problems with using the right spec injector are needing spacers for the fuel rail and different plug surely this is not a major drama?

[prj]

Is 1.5ms correct?

http://www.bmotorsports.com/shop/product_info.php/products_id/448

http://injector-rehab.com/shop/lag.html

Offset and linearity error / minipw are completely different things.
Offset or injector dead time or injector lag time is the difference between opening and closing time. It depends on voltage and fuel pressure.

Look, to accurately deliver fuel, the ECU needs to know the amount of air entering the engine (it does this using the MAF) and the characteristics of the injectors.
This means that it needs to know how long the injectors have to stay open to reach a certain AFR.

Now let's talk a bit about lag time - basically if your injectors has a lag time of 0.5ms at 12V and 3 bar fuel pressure it means that if you trigger the injector for 1ms, it will do nothing for 0.5ms and spray fuel for 0.5ms. The ECU needs these values for correct fuel delivery.

Now, minimum pulsewidth is the minimum at which the injectors are still linear.
If you go below the linear spot, and let's say your ECU is mapped to 0.5ms at 12V and 3 bar, then suddenly it will deliver more/less fuel for the same kind of air, because lag time won't be 0.5ms anymore. It could be more or could be less, however from 1.5ms until 9ms the lag time will be pretty consistent and the ECU will deliver fuel correctly.

With a 630cc injector, the pulsewidth at idle is below 1.5ms. This means the ECU can not deliver fuel properly.
The closed-loop lambda fuelling will correct it to some extent, but you will still have worse fuel economy and the engine will be less refined at low loads.

http://cgi.ebay.co.uk/5-EV14-Volvo-B...item5639777376

http://cgi.ebay.co.uk/5-EV14-Volvo-B...item5643cf7991

How about using EV14 650cc or 750cc with adaptors then? too big? Price seems reasonable.

Sorry if anyone is fed up of this thread

I'd say 650cc's are too big. Haven't really tried them, but Motronic's precision might start getting in the way at low pulsewidths.
Get 550's - they'll be enough for 500-540hp and I doubt you will have more on Motronic anyway.

[URquattroGus]

Ross You have PM

[fridtjov-audirs2]

[QUOTE=prj;

I'd say 650cc's are too big. Haven't really tried them, but Motronic's precision might start getting in the way at low pulsewidths.
Get 550's - they'll be enough for 500-540hp and I doubt you will have more on Motronic anyway.[/QUOTE]


I have buy 80 lb/h deka but if al deka is so bad I want to buy some new.....

I am going for 600 ++ and runing autronic plug/play to Motronic

[Billman]

If you already have them just use them and see what happens. Many many engines are running with decks mostly 630 ones.

[diesel des]

Yep I run them and they seem ok. Sure new Bosch look better, but I ain't buying twice.

[dkw_dude]

I'm running 840cc/3bar Siemens Deka from EfiExpress, works fine for me on VEMS